Sedimentary Characteristics and Sedimentary Model of Xishanyao Formation in Shanle Oilfield

Based on the analysis of the regional geology,seismic data,logging data and core data,the sedimentary characteristics and sedimentary model of Xishanyao formation in Shanle oilfield were investigated.The results show that lacustrine,delta,and fan delta facies are the three types of sedimentary facies in the Xishanyao formation.Fan delta deposit which originated from the Bogda mountain in the Northern part is mainly developed in the first segment of Xishanyao formation,while in the south,delta deposit originated from the Jueluotage mountain is widely developed in the first and second segments of Xishanyao formation.Lacustrine deposit is mainly distributed in the third and fourth segments of Xishanyao formation.Under the control of North-South bidirectional sources,Xishanyao formation underwent three main stages of sedimentary evolution:the lake basin-filling phase controlled by North-South bidirectional sources of the first segment of Xishanyao formation,the North steady delta sedimentation phase of the second segment and the deep-vast water expansion sedimentation phase of the third and fourth segments.